Certain imidazo[1,2-a]-s-triazines including the base, the nucleoside, and the nucleotide are prepared and have been tested and found to be biologically active as an antiviral agent for RNA type viruses.
Over the last three decades medical science has discovered and learned to use chemotherapeutic agents having activity against microorganisms including bacterium and certain fungi. Excluded from this group have been agents which are active against viruses. In the last few years research has been centered on finding effective chemotherapeutic antiviral agents. At present there are only a very few compounds known to be active against viruses.
In search of biologically active compounds, scientists have realized and have been able to understand in great detail the function of many of the biological pathways active within living organisms. With this understanding has come the realization that certain synthetic compounds might be designed which will mimic naturally occurring compounds in respect to their ability to interact with appropriate binding sites on enzymes and other important biological constituents. Many derivatives of naturally occurring compounds such as nucleosides and nucleotides have been prepared but only a select few have expressed the necessary biological activity.
The imidazo[1,2-a]-s-triazine ring system is related to the naturally occurring purine ring system in that certain of the nitrogen atoms in the ring system of the above noted triazine ring are placed in positions which correspond to the same positions in the purine ring. While many different ring systems have been prepared in attempts to mimic the biological activity of the purine ring system the imidazo [1,2-a]-s-triazine ring system has not until very recently been prepared. The compounds of the present invention have an amino group and a keto group in what corresponds to the 2 and 6 positions, respectively, of the purine ring. As such they are related to the purine guanine. Guanine itself is not active as an antiviral agent but is found as its nucleotide in both RNA and DNA.
Recently we published a paper describing the preparation of the instant system in the Journal of Medicinal Chemistry, 1978, Volume 21, number 9, 883, the entire disclosure of which is herein incorporated by reference. Additionally, two other papers have appeared in the literature describing this ring system. These papers are both by Prisbe et al. in The Journal of Organic Chemistry, Volume 43, No. 25, 1978, 4774 and 4784.